Along this line, our group has shown that biostable B1R or B2R agonists promote the selective delivery of co-injected diagnostic MRI agents (e.g., Magnevist (0.5 kDa) and Gadomer (17 kDa)) or the chemotherapeutic drug carboplatin (0.4 kDa) across the BBB, within experimental malignant brain tumors (i.e., F98-Fischer syngeneic rat glioma model) [18,19,20]. Here, BDKRB2 is linked to central nervous system cancer.